Electrode structure and substrate processing apparatus

Abstract

An electrode structure capable of adequately increasing an electron density in a processing space at a part facing a circumferential edge portion of a substrate. In a processing chamber of a substrate processing apparatus that performs RIE processing on a wafer, an upper electrode of the electrode structure is disposed to face the wafer placed on a susceptor inside the processing chamber. The upper electrode includes an inner electrode facing a central portion of the wafer and an outer electrode facing the circumferential edge portion of the wafer. The inner and outer electrodes are connected with first and second DC power sources, respectively. The outer electrode has its first secondary electron emission surface extending parallel to the wafer and its second secondary electron emission surface obliquely extending relative to the first secondary electron emission surface.

1 . An electrode structure disposed inside a processing chamber of a substrate processing apparatus for performing plasma processing on a substrate, so as to face the substrate placed on a mounting table in the processing chamber, comprising:
 an inner electrode disposed to face a central portion of the substrate; and   an outer electrode disposed to face a circumferential edge portion of the substrate,   wherein said the inner electrode is connected to a first DC power source,   said outer electrode is connected to a second DC power source, and   said outer electrode has a first surface thereof extending parallel to the substrate and a second surface thereof obliquely extending relative to the first surface of said outer electrode.   
   
   
       2 . The electrode structure according to  claim 1 , wherein the first and second surfaces of said outer electrode are directed toward the circumferential edge portion of the substrate. 
   
   
       3 . A substrate processing apparatus including a processing chamber for housing a substrate, a mounting table disposed inside the processing chamber and adapted to place the substrate thereon, and an electrode structure disposed inside the processing chamber so as to face the substrate placed on the mounting table, the substrate processing being adapted to perform plasma processing on the substrate, wherein:
 the electrode structure includes an inner electrode thereof disposed to face a central portion of the substrate and an outer electrode thereof disposed to face a circumferential edge portion of the substrate,   said inner electrode is connected to a first DC power source and said outer electrode is connected to a second DC power source, and   said outer electrode has a first surface thereof extending parallel to the substrate and a second surface thereof obliquely extending relative to the first surface of said outer electrode.   
   
   
       4 . The substrate processing apparatus according to  claim 3 , wherein the first and second surfaces of said outer electrode are directed toward the circumferential edge portion of the substrate.